One-sided photoetching process for needle fabrication

Abstract

Surgical needles are fabricated by masking and etching a plurality of the needle blanks from one side of a base material, such as a metal sheet, after applying an etchant resistant adhesive backing to the other side and then etching the one side of the sheet as a chemical milling process. The resultant needles are unattached to each other or to the sheet and individually removable from the backing. This increases the speed of manufacturing while maintaining the ease of use.

What is claimed is: 
     
       1. A method for fabricating surgical needle blanks comprising the steps of: selectively masking a first side of an unmasked sheet of base material into chemically resistant patterns corresponding to a plurality of individual surgical needles;   exposing unmasked areas of said masked base material to light to form an etchant resistant coating thereon;   applying an etchant resistant backing to a second side of said base material;   etching away from said base material those areas which do not have said etchant resistant coating to form a sheet with a plurality of individual surgical needle blanks attached to said etchant resistant backing; and   removing said etchant resistant coating from said plurality of individual surgical needles.   
     
     
       2. The method of claim 1, wherein the step of masking includes masking said first side of said base material into patterns corresponding to a plurality of individual surgical needles of various shapes. 
     
     
       3. The method of claim 1, wherein said masking comprises the steps of: coating only said first side of said base material with a photo-resistant material; and   covering said first side of said coated base material with a negative image of a first side of said plurality of individual surgical needles.   
     
     
       4. The method of claim 3, wherein said negative image is on a glass plate. 
     
     
       5. The method of claim 3, wherein the step of masking further comprises baking said base material to harden said coating. 
     
     
       6. The method of claim 4, wherein said baking is at about 100° to 250° for about 10 minutes. 
     
     
       7. The method of claim 1, wherein said backing includes an adhesive backing. 
     
     
       8. The method of claim 1, wherein said backing is removable by means of immersing said base material in a solvent. 
     
     
       9. The method of claim 8, wherein said backing is from the group of vinyl copolymers. 
     
     
       10. The method of claim 1, wherein the step of etching is by immersing said base material in a aqueous solution of hydrochloric acid and ferric chloride. 
     
     
       11. The method of claim 1, wherein the step of etching includes etching a channel within the base material suitable for the attachment of sutures. 
     
     
       12. The method of claim 1, further comprising heat treating the base material and removing the finished plurality of individual surgical needles from the base material. 
     
     
       13. The method of claim 12, wherein each surgical needle of the finished plurality of individual surgical needles is a curved, square bodied needle having a diameter of about 0.006 inches and an average bend movement of about 19 gram centimeters. 
     
     
       14. The method of claim 1, further comprising the step of removing said plurality of individual needle blanks from said etchant resistant backing. 
     
     
       15. A method for fabricating surgical needles comprising the steps of: selectively masking only a first side of an unmasked sheet of base material into chemically resistant patterns corresponding to a plurality of separate and independent surgical needles;   exposing only unmasked areas of said first side masked base material to light of form an etchant resistant coating thereon;   applying an adhesive etchant resistant backing to a second side of said base material to adhere said plurality of separate and independent surgical needles to said backing after etching and in preparation for chemical milling;   etching away from said base material those areas which have not formed the etchant resistant coating and the adhesive etchant resistant backing to form a sheet with a plurality of separate and independent surgical needles attached thereto by said adhesive etchant resistant backing;   removing said etchant resistant coating from said plurality of separate and independent surgical needles; and   chemically milling away from said plurality of separate and independent surgical needles excess base material leaving said plurality of separate and independent surgical needles substantially free of rough edges, flairs and burrs.   
     
     
       16. The method of claim 15, wherein said masking comprises the steps of: coating said first side of said base material with a photo-resistant material; and   covering said first side of said coated base material with a negative image of a first side of said plurality of separate and independent surgical needles.   
     
     
       17. The method of claim 16, wherein said negative image is on a glass plate. 
     
     
       18. The method of claim 15, wherein the step of etching includes etching a channel within the base material suitable for the attachment of sutures. 
     
     
       19. The method of claim 15, wherein the step of chemically milling includes chemically sharpening and smoothing surfaces of said plurality of separate and independent surgical needles. 
     
     
       20. The method of claim 15, wherein said chemically milling is done in an amount sufficient to yield finished surgical needles with substantially no visible striations. 
     
     
       21. The method of claim 15, further comprising the step of removing said plurality of separate and independent surgical needles from said adhesive etchant resistant backing. 
     
     
       22. A method for fabricating surgical needles comprising the steps of: selectively masking only a first side of an unmasked sheet of base material into chemically resistant patterns corresponding to a plurality of unconnected surgical needles;   exposing unmasked areas of said masked base material to light to form an etchant resistant coating thereon;   etching away from said base material those areas which do not have said etching resisting coating thereon to form a sheet with a plurality of surgical needles spaced apart and not connected to any other base material attached to an etchant resistant backing;   removing said etchant resistant coating from said etched base material; and   chemically milling away from said base material leaving said plurality of unconnected surgical needles substantially free of rough edges, flairs and burrs.